Various types of recording devices, such as video cameras and smartphones, include image sensors that can be used to record video. A video may be generated by capturing a sequence of images, which are often called video “frames” and which are typically captured at a defined frame rate (e.g., thirty frames per second). The captured sequence of frames may be presented by a display device at the same frame rate, and the switching from a presentation of one frame to a presentation of another frame may go largely unnoticed by humans, such that the display may appear to present actual motion rather than a sequence of quickly-switching images.
Recording devices are sometimes subject to unintentional movement during recording, for example, shaking that results from the recording device being handheld by a person or attached to a moving vehicle. Such movement can have a particularly significant effect on a video when the movement is rotational and the scene being captured is far away from the recording device.
Various techniques can stabilize video to limit unintentional movement of a recording device. One technique to stabilize video is mechanical stabilization, in which mechanical actuators counteract external forces. Mechanical stabilization can be implemented by mounting the recording device to a secondary device that stabilizes movement of the entire recording device (e.g., a gimbal). Mechanical stabilization can also be implemented by integrating actuators within the recording device to stabilize the camera or portions thereof with respect movement of the main body of the recording device. Another technique to stabilize video is digital video stabilization, in which a computer analyzes video that has been recorded and crops the captured frames in a manner that produces a partially-zoomed-in version of the video that is stabilized. Mechanical stabilization and digital video stabilization techniques may be combined.